Śrīmad-Bhāgavatam 11.17.12
Blended reading (Sanskrit + English inline)
In Tretā-yuga, the bull of religion loses one leg, and only seventy-five percent of religious principles are manifested, represented by the three principal Vedas — Ṛg, Sāma and Yajur. The Lord appears in the process of threefold Vedic sacrifice. The three divisions are understood as follows. The hotā priest offers oblations into the fire and chants the Ṛg Veda; the udgātā priest chants the Sāma Veda; and the adhvaryu priest, who arranges the sacrificial ground, altar, etc., chants the Yajur Veda. In Tretā-yuga such sacrifice is the authorized process for spiritual perfection. The word prāṇāt in this verse refers to the universal form of the Personality of Godhead. This form is further described in the following verses.
My note
Source: vedabase.io